TWEEDLEDUM AND TWEEDLEDEE

Tweedledum and Tweedledee

Agreed to have a battle;

For Tweedledum said Tweedledee

Had spoiled his nice new rattle.

Just then flew down a monstrous crow,

As black as a tar-barrel;

Which frightened both the heroes so,

They quite forgot their quarrel.

(Lewis Carroll, Through The Looking Glass, chapter IV)